[PATCH 2/2] net: ipv4: route.c: Remove unnecessary if()

[Yejune Deng]

negative_advice handler is only called when dst is non-NULL hence the
'if (rt)' check can be removed. 'if' and 'else if' can be merged together.
And use container_of() instead of (struct rtable *).

Signed-off-by: Yejune Deng <yejune.d...@gmail.com>
---
 net/ipv4/route.c | 16 ++++++----------
 1 file changed, 6 insertions(+), 10 deletions(-)

diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 5762d9bc671c..f4ba07c5c1b1 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -814,19 +814,15 @@ static void ip_do_redirect(struct dst_entry *dst, struct 
sock *sk, struct sk_buf
 
 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
 {
-       struct rtable *rt = (struct rtable *)dst;
+       struct rtable *rt = container_of(dst, struct rtable, dst);
        struct dst_entry *ret = dst;
 
-       if (rt) {
-               if (dst->obsolete > 0) {
-                       ip_rt_put(rt);
-                       ret = NULL;
-               } else if ((rt->rt_flags & RTCF_REDIRECTED) ||
-                          rt->dst.expires) {
-                       ip_rt_put(rt);
-                       ret = NULL;
-               }
+       if (dst->obsolete > 0 || rt->dst.expires ||
+           (rt->rt_flags & RTCF_REDIRECTED)) {
+               ip_rt_put(rt);
+               ret = NULL;
        }
+
        return ret;
 }
 
-- 
2.29.0